Transmission synchronizer



NOV. 19, 1940. P @RRv 2,221,897

TRANSMISSION SYNCHRONIZER Filed Nov. 17, 1939 2 Sheets-Sheet l I i l l 2g 20 g3 una J7v J5 J7 J6 fgf 57 l 26 if? J? i Y J7 3 I 3| l l jf jmggg U2 A Nov. 19, 1940. P. @RR '2,221,897 y TRANsMIssIoN SYNGHRONIZER Filed Nov. 17, `i959 2 sheets-sheet 2 l jg 9 .as 7 N/ JO l N 3g 5o ww @i J3 gfx@ f6 ff f j INVENTOR. 55 v \`53 j! FCZ/fmef UPP www@ Patented Nov.19,194o 2,221,891 d ,UNITED STATES l,"2,'za1`,89'z" Y v ,..TRANSMISSIONSYNCHRQNIZER Palmer Orr, Muncie, vInd., fas/signor to `BorgA Warner Corporation, Chicas.` Ill., acorporation of-lllinois d i d Y Application November 17, 1939, Serial No. 304,891 1s claims. (crise-'53) This applicationAis-.in part a continuationlzof sion wherein athrust bar functions notonlyf for my application Serial No.` 216,861, led July -"1,` transmitting thrust',bu't also as tlieffblocking" 1938, for Transmission synchronizer. y means. d

The invention relates to synchronizing'change- Other objects, the advantage'sandV uses ofv thei` speed gear transmissions of the typev employed, inventionwill become more apparent-after readfor example, in motor vehicles, wherein there is ing the'V followingspecification yand claiins, and provided means for eifecting synchronization of after consideration of the drawings forming a a pair or pairs of" torque transmittingsmembersv part of the specification, wherein:l 1 f preparatory to connecting said members in posi- Fig.-1 is an axial sectional view of a transmis lo tive drive engagement with each other by ,means` sion embodying the invention; 'd d f. i lo of an axially movable positive drive element such Fig. 2-is a transverse sectional view of the same as a jaw clutch sleeve or gear.' y i* j' takenasl indicated bythe line 2 2 of Fig; 1; n

'Ihe invention is particularlytdirected tos'ynf Fig. 3 is'a transverse sectional view of the chronizingl transmissions of the type wherein the same, showing the parts ina diierent` 'stage of'V 5. synchronizing` means comprises Africtionvclutch operation; l. d j f- -l elements adapted under axial thrusttransmitter-.l Fig. 4 `is an axial sectional view of a somewhat' toone of such elements from the movable posimodified form of the invention;l l tive drive element, to develop suiiicient frictional Fig`..5j is an axial sectional view of another engagement to cause 'the torque transmitting modification ofthe invention; v' 20 members to assume the'samejspeed of rotation, Fig.` 6 is aI transverse sectional view loffthe- '20 and vwherein. there incorporated so-calledi same ltaken asL indicated by the line-B-B of blockerf mechanism for preventing'the positive` Fig,.5" L o drive engagement of themembers prior to the `l5ig."7'is"a transverse sectional view,- taken as' time that synchronization is effected. I indicated by the line 1-1 of Fig. 5; f j Y' In a widely used kform: of" synchronizer, Ythe Figy8 is a plan .viewf-'ofga'portion'V ofa thrust r2|, blocking means is incorporated in" the movable bar and associatedpportionlof asynchron'izer i friction clutch elementlor synchronizer ringyinring; and y the form of 'lugs or teeth'adapted to be biased Vin n Fig. 9 vis a detail sectional Vviewvof another o blocking relation tothe movable positive drive modicatio-n of'the invention' element as a result .of limited` oscillating move As an example of one'form irrwhichl the'inven.r so ment of the synchronizer ring relativetothe tion-may be embodied, I hav'e'shownin thefdraw member with which is associated. `An object ings the"synchronizingportion"of Ya. 4transmission of the presentinvention is to eliminatethe neembodying a torquejtransmittirig member* I0, l cessity for such'block'er lugsl or'teeth while pre-j forming the'zrear end of the drive shaft ofthe Y 35 serving their function.v y l o y The invention deals also with tliemeans for including thedriven shaft II, piloted yasat I2 transmitting-axial thrust fromfthe' movable posiin themembe' IIL "and thehilbmember I3, tive drive' element to the synchronizerring, and .splined asj at I4- on Vthe driven-shaft Il and. has as one of itsobjectswto provide a transmissecured against axial movementbyretainingf sion of this type 'in which thrust Vtransmittingl rings I5an'd I6. 'Positive drive connection may 'engagement' between the movable'positive drive be established'betweenthe torque transmitting element and the thrust transmitting meansv will members I'Dand II, orfbetween areduc'tion geared be developed as afresult of relativefrotation torque trfar'ismitting'meinber-Il,y and the member existing between the membersto be synchronized; II. by an axially movable J'aW lutrhv element I8, .and will be relaxed when `synchronization is adapted@ be shifted byahftng f01k-I9into 5 transmission,` and torque transmitting members; 35

attained so that the movable drive lelement may positiveclutching engagement withclutchteeth y complete its advance to positive Adriving position. n 20 formed on the torque :transmitting member Other objects .of the invention are to provide" I0, or clutch'teeth 2I`formed on the torque-'transa Atransmission synchronizer requiring a minimitting member I1. fTo this end, the movable n 50 mum of manual effort in the synchronizing op'erjaw Aclutchsleeve I8 is fformed 'With-internal '50 ation,having a minimum number of parts; and clutch teeth' 22, slidingly splinedupon'the peri-ph which is inexpensive'and simple to` manufac@ ery 23a of the hub member I3;'and adapted `*to ture. o engage the vclutch teeth 20'A or `2l when moved To thelatta'inment of these objects, thednvenaxially. L l 1 V 55 tion contemplates a synchronizingvk tnansir'iisjk The torque? transmitting member I1 comprises u part of a reduction gear train driven from the pinion 24 on the drive shaft IIJ through the medium of aconventional countershaft. Upon being moved into clutching engagement with the clutch teeth 20, the sleeve I8 will receive rotation from the drive shaft I0 and transmit it directly through the hub I3 to the driven shaft I I. Upon being moved inthe opposite direction, the sleeve I8 will receive rotation from the torque transmitting member I'I through the countershaft just referred to, and will transmit it through the hub member I3 through the driven shaft .I I.V

In order to synchronize a torque transmitting member I0 or I1 with the hub I3, preparatory to establishing such clutching engagement, I provide a pair of synchronizer rings 25. As shown in Figs. 4 and 5, the hub I3 may havea rim portion 23 defining a pair of axially opening annular recesses 21, and the synchronizer rings 25 may ment of the collars 26 in the recesses 21 or by theengagement of the clutch faces 33 and 34 through the medium of .intervening oil lms indicated at i 30, such films preventing destructive wear.

'In order toA effect clutching engagement between a friction clutch face 3l) and its cooperating friction face 32, a ring 25 is urged axially by axial thrust transmitted to it from the movable clutch sleeve through the medium of thrust bars 5I. A thrust barl 5I is roughlydumbbell-shaped, having a re'duced waist region 52 and radially enlarged heads ,53 forming between them shoulders 54 which, in the preferred form of the in-.l

vention, are f rusto-conical for a purpose which will hereinafter appear. vThe heads `53 are re-` ceived in notches 55 in the synchronizer rings,

the sides of the notches 5 5 forming cam surfaces or ramps adapted, under biasing .of a synchronizer ring as shown in Fig. 2, to force the `heads 53 'radially outwardly, the thrust bars being restrained-'against circumferential, movement by..

recesses 5'I in the hub, in which they `are seated.

The engagement of the ramps against the heads 53 also serves to transmit drive between the rings and the hub.

When a synchronizer ring" has become biased sufficiently to interpose a head `53 in blocking relation to the sleeve Ill,` movementof the sleeve against the head will transmit thrust tothe syn-- chronizer ring, with whichthe heads-are adapted to haveabutting, positivethrust transmitting engagement; and the frictional driving-engagement thus developed between the friction faces,

and 32 will be effective to complete and maintainthebiasing of the ringagainst forces which tend to `return the ring toa neutral lposition as will hereinafterbe more fully pointed out.

Initialbiasing of the ring may be effected in either of two ways. .Where the synchronizer ring is arranged to. ride upon its vcoacting cone through the mediumofan `oil film,there will be a constant transmission of a slight amount of torque to the ring whenever differential rotationexists between the ringand itswcone, and thus the heads 53, when not confined within the sleeve I8, will be maintained in blocking position as shown in full lines in Fig. l.

Where the synchronizer rings are arranged to be normally out of contact with their cooperating cones, as shown in Fig. 9, biasing of a ring may be effected by axial thrust transmitted through the bars 5I during the initial stage of shift-ing movement. Thrust transmitting engagement with the interior of the sleeve I8 may be established by the bearing of the bars against the sleeve under the eiect of centrifugal force. As soon as contact between the ring and the cone is established, the biasing will be completed and Ymaintained in the manner set forth above.

In theforms of theA invention shown in Figs. l

to 4 inclusive',the bars 5I are of sufficient lengthv so that when the sleeve I8 is in its neutral position shown, the heads at both ends of the bars may ymove to blocking position so as to be immediately effective to initiate the synchronizing action upon movement of the sleeve in either direction.`

Iny the form of the vinvention shown in Figs'. 5 to 8 inclusive, the thrust bars are shorter than the axial dimension of the sleeve, so that one end of `each bar is at all times' confined `within the sleeve. rThe blocking action above described will take place` in this vform of the invention whenever the 'movable clutchelement is moved from one positive clutching position to another. When moving to either of the` positive clutching positions after a period of being in neutral position, the thrust bars are adapted to function totransmit thrust .by ramp energizedv pure frictional engagement with the interior'surfacesof the teeth 22.' 'I'hat is,

the heads 53 will develop thrust receiving purely frictional engagement withthe surfaces of theA teeth 22, under radially outward pressure devel,- oped by the camming action of the ramps 56. Increasein axial thrust against the bars 52 from the sleeve I8 will increasethe engagement between the friction members, 32, 33 and 34, Aand this in turn will increase the camming action and thus the thrust transmitting engagementbetween the heads 53 andtheteeth 22. Ingetting intoneutral position, in this formof the invention, .v the action ,is the same as vin shifting from one positive clutching position toanother, except for the nalstage offadvancin'g to the new positive clutching position. After the blocking action has subsided, the movable clutch element is;advanced to, the neutral position and there halted.

At the completion of synchronization, thel synchronizer'rin'g' willbe brought to the neutral position shown invFig. 3 allowing the heads 53 tor be forced radiallyinwardly under the axial pressure of the sleeve I8 exerted against the conical,

shoulders 54 by the ends Aof the teeth22, and the teeth 22 may then ride over the heads 53 into positive clutching engagement with the jaw` clutch t'eeth20'or 2I as the case may be, as indicated in dotted lines in 1. This inwardly camming action may be provided for either by the conical 'aring of the shoulders 54, the inclining ofthefends of theteeth 22, or both.

In the form of the invention shown in Fig. 4,

the bars 5Ia are urged inwardly against the action of centrifugal force by a retractor spring Gli engaged in groovesBI in the several bars. VThe spring 60 may be of suchstrength as to becapable of retracting the bars 5Ia against cen trifugal f orce when differential rotation of the friction surfaces ceases, but adapted to yield under the combined effectief centrifugal force. and; the camming eect of thebiased ring. The form of the invention shown in Fig. 9 substantially.the same as, the form shown in 5 Fig, l, with the exceptionpf the arrangementI of the friction faces. f

1.-.In a synchronizing transmission, a torque -i transmitting member, a synchronizer element.

l adapted under axial pressure toestablish -a synchronizingfrictional driving .connection between said member Aand a `part to be synchronized therewith, an annular positive drive Aelement V- drivingly. connected toy said member and shiftl able axially for estabushing a positive; drivingk connection between said member and saidk part, and acombined blocker and thrust member axially movable within said positive drive element', v said synchronizer element being adapted to have limited Uoscillatory movement relative` to said member and having a camming region adapted during such movement to project` said` Athrust member radially outwardly, said thrust mem.V

berbeing adapted, when thus projected, to` be interposed between said synchronizer element and an end region of said positive drive element so as to transmit axial thrust from said positive drive element to said synchronizer element at the end of an initial stage of axialmovement of said positive driveelement, whereby to leffect synchronization, and to block further axial-advance of said positive drive-element. until synchronizatlon has been completed.

2. In a synchronizing 'transmissiona torque transmittingv member, rav synchronizer element adapted under axial pressure to establish a synchronizing frictional driving connection between said member and a part to'v be synchronized.

therewith, an annular positive drive element driv- 40 ingly connected to said member andshiftzalbl'el axially Vfor establishing a positive driving connection between said member` and said part, and

a combined'blocker and thrust bar disposed within said positive drive element parallel to the axis of said member, and axially movable, saidfsynchronizer element having an oscillatory lost nio-Y tion connection with said member, being adapted to be biased .to one limit of said connection under torque developed by said frictional driving connection, and being Vadapted yto urge'an end region' of said' bar` radially outwardly when thus biased, said end region being adapted, whenithus projected, to be interposed between 'said synchronizer element and an end region of said positive drive element so as to transmit thrust from said. positive drive element tosaid synchronizer ele-" ment at the end of an initial stage of. axial movee,

ment of said positive -drive element, whereby tol effect synchronization, and toblock furtheraxial 00 advance of said positive drive element until synchronization has been completed. Y

3. A synchronizing transmission as deiined in claim l, wherein the blocking portion of said thrust element comprises a radial projection Y formed with an inclined shoulder positioned for` engagement by said end region of the positive drive element and adapted to react to axial pressure from said positive drive element so as to move the `bar radially inwardly out of blockingv position when theprojection of said bar is rey lieved-bythe attainment of synchronization.

4. .A synchronizing :transmission las dened in claim 2, wherein said bar is cylindricaland said end regioncomprises a radially projecting flange.

5. In asynchronizing transmission, a pair of `axially aligned torque-transmitting members,

yaxially aligned shafts, a hub fixed on one of said t. shafts, a pair ofsynchronizer elements each havy ing anosoillatory lostvmotionA connecticm with saidvshub, axially movable relative'4 to said hub, L

.and adapted Vunder axial pressure V"to Vestablish a, 5 synchronizing `frictional.driving connection bef-v tweenY said hub .and a cooperating friction. clutch element carried by the othershafttafjaw clutchy sleeve encirclingand drlvingly connected to said hub and shiftablel axially for establishing a posiv10 tive driving connection *between* said shafts,r and .an axially arranged vthrust bar loosely:mounted",y

between said hub and sleeve for radial movement, f

said` bar having its respectiveendsy formed with radial projections adapted to be moved radially 'u into positions blocking 4the path of,.axial shifting.`v movement of therespective ends. of-said sleeve.' the bar being adapted-when in suchblocking position to receive vthrust from said sleeve and transmit it to a synchronizer element at, the end lof an initial stage of axial lmovement ofsaid Y sleeve, whereby tone'ect-synchronization, andtof.

block-further-axial movement ci' said sleevev synchronization is completed, and said synchronizer `elements being formed with cam m'eans u adapted, when differential rotation exists betweensaid shafts, to engage and projectanadjacent end region of said` bar radially-outwardly f and, when such differential rotationceases, to y allowsuch end region to be moved radially in-j wardly. t f f a- 6. A synchronizing transmission as defined in claim 5, wherein said projections are spaced apart a distance slightly greater than the axial dimension of 4that regionof the sleeve which is engaged- I 7. `A synchronizing transmission asdened inv claim 1, whereinfthe thrustelement is adapted. to react Ato centrifugalv force so as to establish y an initial thrust transmitting relationship be- 40 i tween said positive. drive element and said synchronizer element for insuringinitialbiasingof i the latter. i f

8. A synchronizing transmission as defined inA claim 1, wherein the frictionV surfacesare arranged -so as` to Aconstantly transmit a slight amount of torque'through the-medium -of an in.- terposed oil film when the positive drive element@- is in kneutral position, so as to' insure initial bias-Jl Ving of `th'e synchronizer element.r` 5U l9.'.In a synchronizing transmisslom-arpair lof synchronizer yand movable jawclutch elements 'v drivinglyassociated with one of said members .and movable axially into frictional driving Yand I5 positive clutching engagement,respectively, with, I friction and jaw clutch elements carriedby the 1 other member, so as to establish `first ya. synchronizing and then a positive drive connection between said members, and meansi'or transmit- 0` ting 4axial thrust from said movable clutch elementto saidsynchronizer elementior effecting said frictional drivingengagemenhtomprising,a bar disposedvinside said movable clutch element,

havinga reduced waist region and arrenlargedl 06` l vhead separated by a shoulder, saidsynchronizer element being adaptedto have limitedcircum- 10. In a synchronizing transmission, a pair of axially aligned torque-transmitting members, synchronizer and movable Jaw clutch elements drivingly associated with one of said members and movable axially into frictional driving and positive clutching engagement, respectively, with friction and jaw clutch elements carried by the other member, so as to establish first a synchronizing and then a positive drive connection between said members, and means for transmitting axial thrust from said movable clutch element to said synchronizer element for effecting said frictional driving engagement, comprising a thrust element operatively interposed between said movlo able clutch element and said synchronizer element, said thrust element having a shouldered region, said synchronizer element being adapted to have limited circumferential movement relative to said one torque-transmitting member and 20 having a camming region adapted, during such circumferential movement, to cam said thrust element radially outwardly so as to bring said shouldered region into position to be engaged by said movable clutch element during axial shift- 26 ing of the latter.

11. In a synchronizing transmission, a pair of axially aligned torque-transmitting members, synchronizer and movable jaw clutch elements drivingly associated with one of said members 3 0 and movable axially into frictional driving and positive clutching engagement, respectively, with friction and jaw clutch elements carried by thel other member, so as to establish first a synchronizlng and then a positive drive connection be- 35 tween said members, and means for transmitting axial thrust from said movable clutch element to said synchronizer element for effecting said frictional driving engagement, comprising a thrust element operatively interposed between 40.5aid movable clutch element and said synchronizer element, said thrust element having a shouldered region, said synchronizer element being adapted to have limited circumferential movement relative to said one torque-transmitting 45 member and having an axially opening recess receiving an end 4region of said thrust element, said recess forming a cammed surface adapted during such circumferential movement, tocam said thrust element radially outwardly to a posi- 50 tion wherein said shouldered region will be engaged by said movable clutch element during axial movement of the latter so as to receive axial thrust therefrom.

12. In a synchronizing transmission, a pair of 55 axially aligned torque-transmitting members, synchronizer and movable jaw clutch elements drivingly associated with one of said members and movable axially into frictional driving and positive clutching engagement, respectively, with friction and jaw clutch elements carried by the other member, so as to establish first a synchronizing and then a positive drive connection between said members, and means for transmitting axial thrust from said movable clutch element to 65 said synchronizer element for effecting said frictional driving engagement, comprising a dumbbell-shaped thrust bar disposed inside said movable clutch element with its major axis parallel to the axis of said members, said synchronizer 70 element having an axially opening recess receiving and forming therewith a lost motion connection between said synchronizer element and said one torque-transmitting member, said recess providing a camming surface adapted, during movep'l'ment'of said synchronizer element in said lost motion connection, to cam an end of said bar outwardly so as to dispose one of the heads thereof in obstructing relation to said movable clutch element, so as to receive thrust therefrom.

13.v In a synchronizing transmission, a pair of 5 axially aligned torque-transmitting members, synchronizer and movable jaw clutch elements drivingly associated with one of said members y and movable axially into frictional driving and positive clutching engagement, respectively, with friction and jaw-clutch elements carried by the other member, so as to establish first a synchronizing and then a positive drive connection between'said members, and means for transmitting axial thrust from said movable clutch element l5 to said synchronizer element for effecting said frictional driving engagement, comprising a thrust element having a shoulder and an end in thrust-transmitting engagement with the synchronizer element, said synchronizer element be- I0 -ing adapted to have a limited amount of circumferential movement relative to said one tor'quetransmitting member and having a cam portion adapted, during such circumferential movement, to move said thrust element radially outwardly so as to bring said shoulder into blocking relation to said movable clutch element at the end of an initial stage of axial movement of said movable Jaw clutch element, whereby to effect synchronization, and to block further axial adl. vance of the latter until completion of synchronization.

14. In a synchronizing transmission, a pair of torque transmitting members to be synchronized, a movable Jaw clutch element drivingly associated with one of said members and adapted to be moved into positive clutching engagement with a jaw clutch element drivingly associated with the other member, a friction clutch element ar-` ranged to have limited oscillatory movement relo ative to said one member and to' receive from said movable jaw clutch element, at the end of an initial stage of movement thereof, axial pressure to establish frictional synchronizing engagement with a friction clutch element drivingly associated `with saidother member, and blocker means acted upon by said first mentioned friction clutchelement adapted, when the latter is biased to one limit of said oscillatory movement, to be radially projected into engagement with said movable jaw clutch element for blocking further axial advance thereof until synchronization has been completed. A

15. Ina synchronizing transmission, a pair of torque transmitting members to be synchronized, one of said members comprising a hub,;a jaw clutch sleeve encircling and splined upon said hub and adapted tobe moved axially in positive clutching engagement with a jaw clutch element drivingly associated with said other member, a 00 synchronizer ring axially recessed into saidv hub and arranged io have limited oscillatory movement relative to said hubv and to receive from said sleeve, at the end of aninitial stage of movement thereof, axial pressure to establish fr-ictional synchronizing engagement with a friction clutch element drivingly associated with said other member, a blocker element movably mounted in said hub, engageable by said synchronizer ring, and adapted whenthe latter is biased to one limit of said oscillatory movement, to be projected into engagement with said movable jaw clutch sleeve for blocking furthery axial advance thereof until synchronization` hasbeen completed.

16. In a synchronizing transmission, a pair of 7| torque transmitting members to be synchronized, a jaw clutch element drlvingly associated with one oi said members and movable axially into positive clutching engagement with a `iaw clutch element drivingly associated with the other member, a friction clutch element arranged to have limited oscillating movement relative to said one member and to receive from said movable jaw clutch element, at the end of an initial stage of movement thereof, axial pressure. to establish frictlonal synchronizing engagement with a friction clutch element drivingly associated with said other member, a blocker element having camming engagement with said rst mentioned 'friction clutch element adapted, when the latter is biased to one limit ofV said oscillating movement to be projected into engagement with said movable jaw clutch element for blocking further axial advance thereof until synchronization has been completed. y v

17. In a synchronizing transmission, a pair of torque transmitting members to be synchronized, a jaw clutch element drivingly associated with one of said members and movable axially into positive clutching engagement with a jaw clutch element drivingly associated WithA the other member, a synchronizer element adapted under axial pressure to establish frictional synchronizing engagement with a friction clutch element drivingly associated with saidother member, and a combined blocker and thrust element arranged to transmit thrust from said movable jaw clutch element to said synchronizer element at the end of an initial stage of movement of said movable jaw clutch element and having a part arranged to be interposed in the path of axial movement l of said movable clutch element so as to positively block the final stage of axial movement thereof, said synchronizer element being arranged to have limited oscillatory movement relative to said thrust member, to be biased to one members are rotating asynchronously, and coacting with said thrust element so as to maintain i the latter in its blocking position when thus biased.

18. In a synchronizing tra mission, a pair of 15 axially aligned, torque-tra tting members to be synchronized, movable ja clutch and synchronizer elementsdrivingly asso iated with one member, said jaw clutchl element eing movable axially'and said 'synchronizer element being zo adapted to be urged under axial pressure into positive clutching and frictional driving engage- I ment respectively with jaw and friction clutch elements drivingiy associated with the other member, and a thrust element arranged to trans- 25 mit axial thrust to said synchronizer element and to receive radially outwardly directed thrust therefrom while relative rotation exists between said synchronizer elementand its cooperating friction clutch element, and to be thereby urged so intol engagement with said movable jaw clutch element so as to receive axial thrust therefrom.

/ PALMER. ORR, 

